FLII and Ewing sarcoma: These data interestingly demonstrate phenotypic differences in adult and pediatric hMSCs populations expressing EWS/FLI, suggestive that cells from pediatric sources have a greater proliferative ability, have a EWS/FLI-mediated transcriptome most similar to Ewing sarcoma tumors and cells lines and furthermore, are more likely to show evidence of genetic reprogramming toward a more pluripotent, stem cell phenotype.